Multimedia Broadcast Multicast Service (MBMS) is a broadcasting and multicasting service offered over mobile telecommunications networks such as General System for Mobile communication (GSM) networks, General Packet Radio System (GPRS) networks, Universal Mobile Telecommunication System (UMTS) networks, and the like. The technical specifications for MBMS include 3GPP (3rd Generation Partnership Project) TS 22.146 and 3GPP TS 23.246.
Mobile television (TV) is an example of a service that may be provided over MBMS. Mobile TV is a service to subscribers via mobile telecommunications networks, providing television services to mobile devices.
FIG. 1 illustrates an example of a known architecture 100 for providing MBMS. The architecture 100 comprises an operator network 110, such as a GSM, GPRS or UMTS network.
The operator network 110 comprises a node 112, such as a base station, which is wirelessly coupled to one or more user equipment (UE) devices, a UE comprising by way of example a mobile telephone handset. The operator network 110 further comprises a Gateway GPRS Support Node (GGSN) 114, which is coupled to a Broadcast Multicast Service Centre (BM-SC) 130.
The BM-SC 130 is adapted to provide content, for example Mobile TV content, to the UE 120, by way of broadcasting and/or multicasting content streams. The operator network 110 advertises, or otherwise provides, information publicising available content to UE 120. The UE 120 is then able to request from the operator network 110 the content that it wishes to receive (e.g. subscribe to).
The operator network 110 subsequently informs the BM-SC 130 of the requested content, and informs the UE 120 of the channel(s) on which the requested content will be available, as well as any encryption keys etc. for accessing the content. The BM-SC 130 then provides the content to the network 110, from which the UE 120 is able to obtain the content. As will be appreciated by a skilled artisan, the content may alternatively be provided over a shared MBMS network, as opposed to the operator network 130 such as that illustrated in FIG. 1
Alternative, competing technologies capable of providing Mobile TV and other media services to mobile devices include, by way of example, DVB-H (Digital Video Broadcasting-Handheld), which is a mobile television format for providing broadcast services to mobile handsets, and is defined in ETSI (European Telecommunications Standards Institute) standard EN 302 304. DVB-H is a superset of DVB-T (Digital Video Broadcasting-Terrestrial), a system for digital terrestrial television, with additional features to meet the specific requirements of handheld, battery-powered receivers.
A problem with mobile communication devices is that they experience variable RF (Radio Frequency) coverage and multipath propagation conditions whilst on the move. Accordingly, a mobile communication device receiving media content, for example by way of MBMS or DVB-H, can experience partial or complete data loss when the mobile communication device moves outside of an ‘adequate’ coverage area.
The effect of such partial data loss during playback of media content being received by the mobile communication device may result in simple anomalies in, for example, the video or audio output, which may be deemed acceptable in some circumstances. However, such partial or complete data loss may result in a complete loss of audio and/or video output.
During such a loss of audio and/or video output, a typical reaction of a user is to change ‘channel’ in an attempt to find an alternative media stream. This is known as channel hopping. However, due to the nature of broadcast media technologies, alternative channels are often broadcast on the same frequencies and from the same node (e.g. base station). Consequently, by changing channels, the user may often find that the other channels are also experiencing a loss of data.
As will be appreciated by a skilled artisan, a loss of audio and/or video output is detrimental to a user's experience, which is worsened when alternative channels are also experiencing data loss. Furthermore, receive buffers used within digital media receivers can typically take one or more seconds to fill before playback begins. Accordingly, each time a user changes channel, there is a noticeable delay, thereby further impairing the user's experience.
Thus, there exists a need for an improved method and apparatus for outputting media content on a mobile communication device.